Testing of the pressure of the stylus of pickups



Aug. 1954 E. w. MORTIMER TESTING OF THE PRESSURE OF THE STYLUS OF PICKUP Filed Dec. 5, 1951 Patented Aug. 31 1954 PRES SURE OF THE TESTING OF THE STYLUS O F PICKUPS Edmund Walter Mortimer, Swindon, England, assignor to The Garrard Engineering and Manufacturing Company Limited, Swindon, England Application December 5, 1951, Serial No. 260,058

2 Claims.

tion.

The lever balance system may comprise a pair of levers mounted on arms on the same side manual operation.

In the accompanying drawings:

Figure 1 is a front outside view of the testing device according to the invention.

Figure 2 is an elevation with a part of the front plate of the casing removed to expose the lever balance system.

Figure 3 is an end elevation.

In carrying the invention into effect according gramophone.

Within the casing I a pair of levers 3, 4 are mounted on spaced horizontal fulcra by the aid of suitable pins 5, 6 supported in a vertical rear wall 1 of the casing.

One lever 3 (referred to as the stylus lever) has an arm 3a projecting forwardly from its fulof this arm 3a and located somewhat forwardly of the fulcrum pin 5 an anchorage 5' is formed for the lower end of a coiled spring l0.

On the other side of the lever 3 is provided with a pointer arm 30 the end Sid of across a window II in a removable front wall ll of the casing i. Associated with the window II is a balance indicating mark [3.

The second lever 4 (referred to as manual lever) is fulcrummed on a horizontal axis parallel to and rearwardly of the fulcrum of the stylus lever 3. distance between the axes of zero or balance mark Pressure is then applied to the finger piece 14 to move the manual lever 4, stressing the spring to and causing the stylus lever 3 to pivot until the pointer 311 is in alignment with the balance mark I 3.

The pressure of the stylus will then be read from the scale I 6 being indicated by the position of the finger piece 14 along the scale.

Adjustment of the loading of the stylus, if necessary, may then be made.

I claim:

1. In a device for testing the pressure of a phonograph pick-up stylus, a lever balance sys- 2,687 ,643 I tern comprising a first lever, pivotally mounted 2. In a device for testing the pressure of a intermediate its ends about a horizontal axis, a phonograph pick-up stylus in accordance with stylus supporting means at one end of said lever, claim 1, wherein the spring extends substantially an indicator at the other end of said lever, a vertically and exerts an upward force on the balance indicating means adjacent said indioa- 5 stylus supporting arm.

tor, a second lever, pivotally mounted intermediate its ends about a horizontal axis parallel to, References Cited in the file of this p t and horizontally spaced from, said first men- UNITED STATES PATENTS tioned axis one arm of said second lever extend- Number Name Date ing beyond the pivotal axis of said first lever and 10 the end of said last mentioned arm being posi- 1647287 Floyd 1927 tioned above the stylus supporting arm of said FOREIGN PATENTS first lever, a spring connecting said last men- Number Country Date tioned end and said stylus supporting arm, the 506,284 France May 26 1920 other end of said second lever being manually 15 350,590 Great Britain June 13 1931 movable and a load indicating scale cooperating with said manually movable end. 

